The present invention relates generally to blood filter devices having an associated balloon occluder for temporary placement in a blood vessel, and more particularly to a cannula device, having an associated blood filter and balloon occluder, for placement in a blood vessel to carry blood to an artery from a bypass-oxygenator system and to capture embolic material in the vessel. The invention also relates to catheters having a balloon occluder and associated filter to capture embolic material. More particularly, the invention relates to a blood filter device to be placed in the aorta during cardiac surgery, the device further having a balloon occluder which, when deployed, reduces or eliminates the need for aortic cross-clamping. The present invention also relates to methods for temporarily filtering blood to capture and remove embolic material, and to methods for protecting a patient from embolization which may be caused by the balloon occluder having dislodged atheromatous material from the artery.
Currently, the most common method of temporarily occluding the ascending aorta during open heart surgery utilizes a mechanical cross clamp. Once the chest cavity has been opened, access to the heart and to the adjacent vessels is provided. The ascending aorta is partially dissected from the surrounding tissue and exposed. Arterial and venous cannulas are inserted and sutured into place. The cannulas are connected to the cardiopulmonary bypass machine, and bypass blood oxygenation is established.
At this point, the heart must be arrested and isolated from the rest of the circulatory system. A mechanical cross clamp is positioned between cardioplegia cannula and the aortic cannula and actuated. The aorta is completely collapsed at the clamp site, thus stopping flow of blood between the coronary arteries and the innominate artery the oxygenated bypass blood is shunted around the heart. Once the vessel occlusion has been completed, cardioplegia solution is introduced through the cardioplegia cannula to arrest the heart. The surgeon may now proceed with the desired operation.
Other less common means of occluding the aorta include percutaneous balloon catheter occlusion, direct aortic balloon catheter (Foley) occlusion, aortic balloon occluder cannula, and an inflating diaphragm occluder (Hillxe2x80x94occlusion trocar). The percutaneous balloon catheter is inserted typically from the femoral artery feed through the descending aorta, across the aortic arch into position in the ascending aorta. Once in the ascending aorta, the balloon occluder is inflated and flow stopped.
As a simple replacement for the mechanical cross clamp, a Foley catheter may be placed through an additional incision site near the standard cross clamp site. Once inserted, the Foley catheter balloon is inflated and flow is stopped. Similarly, an aortic balloon occluder cannula is placed directly into the aorta. This occluder cannula replaces the standard aortic cannula by delivering the CPB blood back to the arterial circulatory system. The occluder balloon is located on the cannula proximal to CPB blood exit port on the cannula. It may also replace the need for a cardioplegia cannula with an additional infusion port proximal to the occluder balloon. The occlusion trocar is described to offer similar features as the aortic balloon occluder cannula and would be used in place of the standard aortic cannula. However, it relies on an inflatable diaphragm to occlude the vessel.
The use of a balloon to occlude an artery has been disclosed by Gabbay, U.S. Pat. No. 5,330,451 (this and all other references cited herein are expressly incorporated by reference as if fully set forth in their entirety herein). The Gabbay device included a perfusion cannula having a proximal balloon occluder and a distal intra-aortic balloon to divert blood to the carotid arteries. The Gabbay perfusion cannula is disclosed for use during open heart surgery in order to prevent complications associated therewith.
Moreover, Peters, U.S. Pat. No. 5,433,700, discusses a method for inducing cardioplegic arrest using an arterial balloon catheter to occlude the ascending aorta. The Peters method includes the steps of maintaining systemic circulation using peripheral cardiopulmonary bypass, venting the left side of the heart, and introducing a cardioplegic agent into the coronary circulation. This procedure is said to prepare the heart for a variety of surgical procedures. Disclosures of similar endovascular occlusion catheters can be found in Machold et al., U.S. Pat. No. 5,458,574, Stevens, International Application No. PCT/US93/12323, and Stevens et al., International Application No. PCT/US94/12986.
There are a number of known devices designed to filter blood. The vast majority of these devices are designed for permanent placement in veins, in order to trap emboli destined for the lungs. For example, Kimmell, Jr., U.S. Pat. No. 3,952,747, discloses the so-called Kimray-Greenfield filter. This is a permanent filter typically placed in the vena cava comprising a plurality of convergent legs in a generally conical array, which are joined at their convergent ends to an apical hub. Each leg has a bent hook at its end to impale the internal walls of the vena cava.
Cottenceau et al., U.S. Pat. No. 5,375,612, discloses a blood filter intended for implantation in a blood vessel, typically in the vena cava. This device comprises a zigzagged thread wound on itself and a central strainer section to retain blood clots. This strainer section comprises a meshed net and may be made from a biologically absorbable material. This device is also provided with attachment means which penetrate into the wall of the vessel.
Gunther et al., U.S. Pat. No. 5,329,942, discloses a method for filtering blood in the venous system wherein a filter is positioned within a blood vessel beyond the distal end of a catheter by a positioning means guided through the catheter. The positioning means is locked to the catheter, and the catheter is anchored to the patient. The filter takes the form of a basket and is comprised of a plurality of thin resilient wires. This filter can be repositioned within the vessel to avoid endothelialization within the vessel wall.
Similarly, Lefebvre, French Patent No. 2,567,405, discloses a blood filter for implantation by an endovenous route into the vena cava. The filter is present in the form of a cone, and the filtering means may consist of a flexible metallic grid, or a flexible synthetic or plastic grid, or a weave of synthetic filaments, or a non-degradable or possibly bio-degradable textile cloth. In order to hold the filter within the vein, this device includes flexible rods which are sharpened so that they may easily penetrate into the inner wall of the vena cava.
There are various problems associated with permanent filters. For example, when a filter remains in contact with the inner wall of the vena cava for a substantial period of time, endothelialization takes place and the filter will subsequently become attached to the vena cava. This endothelialization may cause further occlusion of the vessel, thereby contributing to the problem the filter was intended to solve. Except for the Gunther device, these prior art filters do not address this problem.
A temporary venous filter device is disclosed in Bajaj, U.S. Pat. No. 5,053,008. This device treats emboli in the pulmonary artery which, despite its name, is in fact a vein. The Bajaj device is an intracardiac catheter for temporary placement in the pulmonary trunk of a patient predisposed to pulmonary embolism because of hip surgery, stroke or cerebral hemorrhage, major trauma, major abdominal or pelvic surgery, neurosurgery, neoplasm, sepsis, cardiorespiratory failure or immobilization.
The Bajaj device includes an umbrella made from meshwork which traps venous emboli before they reach the lungs. This device can also lyse emboli with a thrombolytic agent such as tissue plasminogen activator (TPA), destroy emboli with high velocity ultrasound energy, and remove emboli by vacuum suction through the lumen of the catheter. This very complex device is designed for venous filtration and is difficult to justify when good alternative treatments exist.
There are very few intravascular devices designed for arterial use. A filter that functions not only in veins, but also in arteries must address additional concerns because of the hemodynamic differences between arteries and veins. Arteries are much more flexible and elastic than veins and, in the arteries, blood flow is pulsatile with large pressure variations between systolic and diastolic flow. These pressure variations cause the artery walls to expand and contract. Blood flow rates in the arteries vary from about 1 to about 5 L/min.
Ginsburg, U.S. Pat. No. 4,873,978, discloses an arterial device. This device includes a catheter that has a strainer device at its distal end. This device is normally used in conjunction with non-surgical angioplasty treatment. This device is inserted into the vessel downstream from the treatment site and, after the treatment, the strainer is collapsed around the captured emboli, and the strainer and emboli are removed from the body. The Ginsburg device could not withstand flow rates of 5 L/min. It is designed for only small arteries and therefore could not capture emboli destined for all parts of the body. For example, it would not catch emboli going to the brain.
Ing. Walter Hengst GmbH and Co, German Patent DE 34 17 738, discloses another filter which may be used in the arteries of persons with a risk of embolism. This filter has an inherent tension which converts the filter from the collapsed to the unfolded state, or it can be unfolded by means of a folding linkage system. This folding linkage system comprises a plurality of folding arms spaced in parallel rows along the longitudinal axis of the conical filter (roughly similar to branches on a tree). The folding arms may be provided with small barbs at their projecting ends intended to penetrate the wall of the blood vessel to improve the hold of the filter within the vessel.
Moreover, da Silva, Brazil Patent Application No. PI 9301980A, discusses an arterial filter for use during certain heart operations where the left chamber of the heart is opened. The filter in this case is used to collect air bubbles in addition to formed particles such as platelet fibrin clots not removed on cleaning the surgical site.
Each of the existing methods of blocking aortic blood flow carries with it some undesired aspects. The mechanical cross clamp offers simplicity and reliably consistent operation. However, the physical clamping action on the vessel has been linked to may adverse body responses. Barbut et al. noted the majority of embolic events (release) is associated with the actuation and release of the cross clamp during coronary bypass graph surgery. The clamping action may be responsible for breaking up and freeing atherosclerotic buildup on the vessel walls. In addition, the potential for vascular damage, like aortic dissections, may also incur during the clamp application.
The percutaneous balloon catheter occluder has a distinct drawback in that it must be placed with visionary assistance. Fluoroscopy is typically used to position the device in the aorta. This added equipment is not always readily available in the surgical suite. In addition, the catheter placement up to the aorta may also create additional vascular trauma and emboli generation.
The use of a Foley catheter to occlude the aorta requires an additional incision site to place the device. This extra cut is an additional insult site and requires sutures to close. Generation of emboli and the potential of aortic dissection directly associated with just the incision may potentially outweigh the benefits of using the balloon occlusion technique.
The aortic balloon occluder cannula addresses many of the deficiencies of the previous devices. Placement is easy to visualize and no extra cuts are required. With the cardioplegia port included, this design offers a complete package while potentially reducing the number of incision sites and removing the need for the potentially traumatic cross clamp. However, this xe2x80x9call-in-onexe2x80x9d design possesses several deficiencies. First, there is one inherent drawback with using a balloon to occlude a vessel. Balloons are always susceptible to failure (e.g., popping, leaking). In addition, the cannula has a limited placement region. It must be inserted sufficiently proximal to the innominate artery to allow room for occlusion balloon to seat within the vessel and not occlude or block the innominate artery. This cannula design has at least two critical functions (three with the cardioplegia port). A balloon failure means either replacing the cannula (stopping the CPB and cardioplegia), or immediately placing the cross clamp and inserting a cardioplegia cannula. Life support, occlusion, and cardioplegia depend on one device. This situation is less than optimal. The risks associated to a failure are multiplied when one device is used for more than one critical operation.
A need exists for an arterial cannula having both a balloon occluder, which reduces or eliminates the need for aortic cross-clamping, a major contributor to atheromatous embolization, and an associated filter which captures any embolic material dislodged during balloon occlusion. Existing devices are inadequate for this purpose.
The present invention relates to arterial medical devices, and particularly cannulas and catheters having an occlusion balloon and optionally a blood filter device, and to methods of using the devices during cardiac surgery. The devices of the present invention may be adapted to filter embolic material from the blood. Embolic material or foreign matter is any constituent of blood, including gaseous material and particulate matter, which may cause complications in the body if allowed to travel freely in the bloodstream. This matter includes but is not limited to atheromatous fragments, fat, platelets, fibrin, clots, or gaseous material.
In one embodiment, the device includes a blood cannula having a balloon occluder at a distal region of the blood cannula. In another embodiment, the device includes an intravascular catheter having a balloon occluder at a distal region of the catheter. The balloon occluder may consist of a flexible material surrounding a chamber which is expandable between a deflated, contracted condition and an inflated, enlarged condition. The balloon occluder may be circumferentially disposed about a distal region of the catheter or blood cannula, or may be attached to the catheter or blood cannula at a specific radial position about the distal region of the catheter or blood cannula. The balloon occluder, when in the contracted condition, is closely associated with the distal region of the catheter or blood cannula, while the balloon occluder expands upon inflation to occupy an area which may occlude blood flowing within an artery.
In another embodiment, the blood cannula or catheter will further include filtration means disposed about the distal region of the catheter or blood cannula. Several designs for blood filtration cannulas are disclosed in Barbut et al., U.S. application Ser. No. 08/553,137, filed Nov. 7, 1995, Barbut et al., U.S. application Ser. No. 08/580,223, filed Dec. 28, 1995, Barbut et al., U.S. application Ser. No. 08/584,759, filed Jan. 9, 1996, and Barbut et al., U.S. Pat. No. 5,769,816, filed on Apr. 30, 1996, and Barbut et al., U.S. Pat. No. 5,989,281, filed Apr. 16, 1997, and the contents of each of these prior applications are incorporated herein by reference in their entirety. Thus, in one embodiment, the balloon aortic cannula as disclosed herein will include a filtration means having an expandable member, such as an inflation seal, disposed about the distal end of the blood cannula, which is expandable between a deflated, contracted condition and an inflated, enlarged condition. The filtration means will further include a mesh having an edge attached to the expansion means. The mesh may optionally include a second edge which is closely associated with the outer surface of the blood cannula, or the mesh may be continuous and unbroken at its distal region. The filtration means will generally be disposed about the distal end of the blood cannula and the balloon occluder at a region proximal of the mesh, so that the balloon occluder expands upon inflation to substantially occlude an artery upstream of the mesh. For those embodiments using an intravascular catheter, the balloon occluder is typically upstream of the filtration means, or with reference to the catheter, distal the filtration means.
In another embodiment, a cannula with filtration means further includes a blood flow diffuser. The blood flow diffuser may be located inside or outside of the blood cannula. In both the intra-cannula and extra-cannula diffuser embodiments, the flow diffuser can be located either proximal or distal to the filtration means. The diffuser may be similarly used for intravascular catheter embodiments of the device.
In another embodiment, a cannula with attached filtration means includes a sleeve which, when unrolled, captures the filtration means thereby closely securing the filter components against the cannula wall during insertion and retraction. The sleeve may be similarly used for intravascular catheter embodiments of the device. In another embodiment, a cannula is made of an elastomeric material which collapses along part of the cannula length so as to absorb the filtration means during cannula insertion and retraction.
In an alternate embodiment, a blood cannula includes a conduit to provide a solution, such as cardioplegia solution, to the heart side of an aortic balloon occluder while providing oxygenated blood into the arterial circulation of the systemic side of the occluder.
The methods of the present invention include protecting a patient from embolization during cardiac surgery by using a balloon aortic cannula as described above or other intravascular or intra-arterial procedure resulting in distal embolization. The distal end of the arterial cannula is inserted into a patient""s aorta while the filtration and expansion means is in the contracted condition. The expansion means, including associated mesh, is inflated to expand and thereby achieve contact with the inner wall of the artery, preferably the aorta. Once the filtration means are in place and deployed, the balloon occluder is activated by inflating to occlude the artery, preferably the aorta, in a region upstream of the mesh. In other embodiments, the balloon occluder may be inflated before the expansion means is inflated. During balloon occlusion, certain embolic material may be dislodged from the artery, and thereafter captured by the deployed filtration system. The cannula is used to supply blood to the aorta from a bypass-oxygenator machine. A surgical procedure may then be performed on the heart, aorta, or vasculature upstream of the deployed filtration system. During this procedure, further embolic material may be dislodged and enter the circulation, and thereafter be captured by the deployed filtration mesh. After the surgery is performed, the balloon occluder is deflated, and further embolic material may be dislodged and captured by the filtration system. The expansion means of the filtration system is then contracted by deflating to resume a small shape, and the arterial cannula with captured embolic material is removed from the aorta.
In a preferred method, balloon occlusion occurs, and blood is filtered during cardiac surgery, in particular during cardiac bypass surgery, to protect a patient from embolization. In this method, the mesh is positioned in the aorta where it filters blood before it reaches the carotid arteries, brachiocephalic trunk, and left subclavian artery.
The present invention was developed, in part, in view of a recognition of the occurrence of embolization during cardiac surgery. Emboli are frequently detected in cardiac surgery patients and have been found to account for neurologic, cardiac and other systemic complications. Specifically, embolization appears to contribute significantly to problems such as strokes, lengthy hospital stays and, in some cases, death. Of the patients undergoing cardiac surgery, 5-10% experience strokes and 30% become cognitively impaired. In addition, it has been recognized that embolization is often the result of procedures performed on blood vessels such as incising, clamping, and cannulation, wherein mechanical or other force is applied to the vessel. See, for example, Barbut et al., xe2x80x9cCerebral Emboli Detected During Bypass Surgery Are Associated With Clamp Removal,xe2x80x9d Stroke 25(12):2398-2402 (1994), which is incorporated herein by reference in its entirety. These procedures are commonly performed in many different types of surgery including cardiac surgery, coronary artery surgery including coronary artery bypass graft surgery, aneurysm repair surgery, angioplasty, atherectomy, and endarterectomy, including carotid endarterectomy. It has also been recognized that reintroducing blood into blood vessels with a cannula or catheter during these procedures can dislodge plaque and other emboli-creating materials as a result of blood impinging upon the vessel wall at high velocities. See, for example, Cosgrove et. al., Low Velocity Aortic Cannula, U.S. Pat. No. 5,354,288.
Finally, it has been found that the occurrence of embolization is more likely in certain types of patients. For example, embolization occurs more frequently in elderly patients and in those patients who have atheromatosis. In fact, atheromatous embolization, which is related to severity of aortic atheromatosis, is the single most important contributing factor to perioperative neurologic morbidity in patients undergoing cardiac surgery.
Embolic material, which has been detected at 2.88 mm in diameter, will generally range from 0.02 mm (20 xcexcm) to 5 mm, and consists predominantly of atheromatous fragments dislodged from the aortic wall and air bubbles introduced during dissection, but also includes platelet aggregates which form during cardiac surgery. See Barbut et al., xe2x80x9cDetermination of Embolic Size and Volume of Embolization During Coronary Artery Bypass Surgery Using Transesophageal Echocardiography,xe2x80x9d J. Cardiothoracic Anesthesia (1996). These emboli enter either the cerebral circulation or systemic arterial system. Those entering the cerebral circulation obstruct small arteries and lead to macroscopic or microscopic cerebral infarction, with ensuing neurocognitive dysfunction. Systemic emboli similarly cause infarction, leading to cardiac, renal, mesenteric, and other ischemic complications. See Barbut et al., xe2x80x9cAortic Atheromatosis And Risks of Cerebral Embolization,xe2x80x9d Journal of Cardiothoracic and Vascular Anesthesia 10(1):24-30 (1996), which is incorporated herein by reference in its entirety.
Emboli entering the cerebral circulation during coronary artery bypass surgery have been detected with transcranial Doppler ultrasonography (TCD). TCD is a standard visualization technique used for monitoring emboli in the cerebral circulation. To detect emboli using TCD, the middle cerebral artery of a bypass patient is continuously monitored from aortic cannulation to bypass discontinuation using a 2 MHZ pulsed-wave TCD probe (Medasonics-CDS) placed on the patient""s temple at a depth of 4.5 to 6.0 cm. The number of emboli is determined by counting the number of embolic signals, which are high-amplitude, unidirectional, transient signals, lasting less than 0.1 second in duration and associated with a characteristic chirping sound.
TCD is useful in analyzing the relationship between embolization and procedures performed on blood vessels. For example, the timing of embolic signals detected by TCD have been recorded along with the timing of procedures performed during open or closed cardiac surgical procedures. One of these procedures is cross-clamping of the aorta to temporarily block the flow of blood back into the heart. It has been found that flurries of emboli are frequently detected after aortic clamping and clamp release. During the placement and removal for the clamps, atheromatous material along the aortic wall apparently becomes detached and finds its way to the brain and other parts of the body. Similarly, flurries of emboli are also detected during aortic cannulation and inception and termination of bypass.
Transesophageal echocardiography (TEE), another standard visualization technique known in the art, is significant in the detection of conditions which may predispose a patient to embolization. TEE is an invasive technique, which has been used, with either biplanar and multiplanar probes, to visualize segments of the aorta, to ascertain the presence of atheroma. This technique permits physicians to visualize the aortic wall in great detail and to quantify atheromatous aortic plaque according to thickness, degree of intraluminal protrusion and presence or absence of mobile components, as well as visualize emboli within the vascular lumen. See, for example, Barbut et al., xe2x80x9cComparison of Transcranial Doppler and Transesophageal Echocardiography to Monitor Emboli During Coronary Bypass Surgery,xe2x80x9d Stroke 27(1):87-90 (1996) and Yao, Barbut et al., xe2x80x9cDetection of Aortic Emboli By Transesophageal Echocardiography During Coronary Artery Bypass Surgery,xe2x80x9d Journal of Cardiothoracic Anesthesia 10(3):314-317 (May 1996), and Anesthesiology 83(3A):A126 (1995) which are incorporated herein by reference in their entirety. Through TEE, one may also determine which segments of a vessel wall contain the most plaque. For example, in patients with aortic atheromatous disease, mobile plaque has been found to be the least common in the ascending aorta, much more common in the distal arch and most frequent in the descending segment. Furthermore, TEE-detected aortic plaque is unequivocally associated with stroke. Plaque of all thickness is associated with stroke but the association is strongest for plaques over 4 mm in thickness. See Amarenco et al., xe2x80x9cAtherosclerotic disease of the aortic arch and the risk of ischemic stroke,xe2x80x9d New England Journal of Medicine 331:1474-1479 (1994).
Another visualization technique, intravascular ultrasound, is also useful in evaluating the condition of a patient""s blood vessel. Unlike the other techniques mentioned, intravascular ultrasound visualizes the blood vessel from its inside. Thus, for example, it may be useful for visualizing the ascending aorta overcoming deficiencies of the other techniques. In one aspect of the invention, it is contemplated that intravascular ultrasound is useful in conjunction with devices disclosed herein. In this way, the device and visualizing means may be introduced into the vessel by means of a single catheter.
Through visualization techniques such as TEE epicardial aortic ultrasonography and intravascular ultrasound, it is possible to identify the patients with plaque and to determine appropriate regions of a patient""s vessel on which to perform certain procedures. For example, during cardiac surgery, in particular, coronary artery bypass surgery, positioning a probe to view the aortic arch allows monitoring of all sources of emboli in this procedure, including air introduced during aortic cannulation, air in the bypass equipment, platelet emboli formed by turbulence in the system and atheromatous emboli from the aortic wall. Visualization techniques may be used in conjunction with a blood filter device to filter blood effectively. For example, through use of a visualization technique, a user may adjust the position of a blood filter device, and the degree of actuation of that device as well as assessing the efficacy of the device by determining whether foreign matter has bypassed the device.
It is an object of the present invention to eliminate or reduce the problems that have been recognized as relating to embolization. The present invention is intended to capture and remove emboli in a variety of situations, and to reduce the number of emboli by obviating the need for cross clamping. For example, in accordance with one aspect of the invention, blood may be filtered in a patient during procedures which affect blood vessels of the patient. The present invention is particularly suited for temporary filtration of blood in an artery of a patient to capture embolic debris. This in turn will eliminate or reduce neurologic, cognitive, and cardiac complications helping to reduce length of hospital stay. In accordance with another aspect of the invention, blood may be filtered temporarily in a patient who has been identified as being at risk for embolization.
As for the devices, one object is to provide simple, safe and reliable devices that are easy to manufacture and use. A further object is to provide devices that may be used in any blood vessel. Yet another object is to provide devices that will improve surgery by lessening complications, decreasing the length of patients"" hospital stays and lowering costs associated with the surgery. See Barbut et al., xe2x80x9cIntraoperative Embolization Affects Neurologic and Cardiac Outcome and Length of Hospital Stay in Patients Undergoing Coronary Bypass Surgery,xe2x80x9d Stroke (1996).
The devices disclosed herein have the following characteristics: can withstand high arterial blood flow rates for an extended time; include a mesh that is porous enough to allow adequate blood flow in a blood vessel while capturing mobile emboli; can be used with or without imaging equipment; remove the captured emboli when the operation has ended; will not dislodge mobile plaque; and can be used in men, women, and children of varying sizes.
As for methods of use, an object is to provide temporary occlusion and filtration in any blood vessel and more particularly in any artery. A further object is to provide a method for temporarily filtering blood in an aorta of a patient before the blood reaches the carotid arteries and the distal aorta. A further object is to provide a method for filtering blood in patients who have been identified as being at risk for embolization. Yet a further object is to provide a method to be carried out in conjunction with a blood filter device and visualization technique that will assist a user in determining appropriate sites of filtration. This visualization technique also may assist the user in adjusting the blood filter device to ensure effective filtration. Yet a further object is to provide a method for filtering blood during surgery only when filtration is necessary. Yet another object is to provide a method for eliminating or minimizing embolization resulting from a procedure on a patient""s blood vessel by using a visualization technique to determine an appropriate site to perform the procedure.
Another object is to provide a method for minimizing incidence of thromboatheroembolisms resulting from cannula and catheter procedures by coordinating filtration and blood flow diffusion techniques in a single device. Another object is to provide a method of inserting or retrieving a cannula or catheter with attached filtering means from a vessel while minimizing the device""s profile and diameter.
Thus, we disclose herein each of the individual designs listed below which are grouped into three categories.